


what if it only gets colder

by tenmilliontrinkets



Category: Haikyuu!!
Genre: Alternate Universe - Fantasy, Blood, Injury, M/M, Mermaid Oikawa
Language: English
Status: In-Progress
Published: 2015-12-02
Updated: 2015-12-10
Packaged: 2018-05-04 11:42:15
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,236
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5332877
Author URL: https://archiveofourown.org/users/tenmilliontrinkets/pseuds/tenmilliontrinkets
Summary: <blockquote class="userstuff">
              <p>"Don't tell me you're planning on fishing here."</p>
            </blockquote>





	1. 1

**Author's Note:**

> the mermaid au i've been dying to write!
> 
> feedback is ever appreciated
> 
> there'll be another part to this, and the title is from "waiting game" from banks
> 
> hohohajime.tumblr.com

“Don't tell me you're planning on fishing here.”

Hajime curses, fumbling, and the hook slips from his hand to hit water the color of ink. It shimmers, dying sunlight ricocheting off of metal, and a ripple of blue turns his head to the whip of a tail too big to belong to something he could catch.

The hook’s dangling in front of him before he can blink, it’s string pinched between pale, slender fingers and swinging like a pendulum. “It’s going to storm any minute now.”

Hajime sighs.

“I’d hoped you things weren’t real,” he mutters and reaches forward, just barely keeping himself from toppling over when the hand’s yanked backwards.

“ _Rude_ ,” The creature whines, “didn’t even thank me.” Hajime sees matted brown hair and eyes too old for the rest of it’s face, features youthful and fair and pretty; he catches himself, lets his gaze linger for a moment until he’s sure this _thing_ is flattered enough, and snatches the hook from its grasp, bolting from the beach with an indignant shout ringing against his eardrums.

He gets caught in the rain on the way home and falls asleep to thunder beating hard against his roof.

 

***

 

“I can’t believe you’re back again.” Hajime doesn’t jump this time, and he’s just a little proud of himself for it. “I could literally curse you. I could make it so you never catch another fish.” Hajime hangs his head over the edge of the dock, searching, and it's perched on a rock right under a broken wooden slat with its lip pushed out in a pout.

“You won’t though,” Hajime responds, and it’s satisfying to see the creature startle and fall off it’s rock. “You’re just a kid.”

“Am _not_. I’m a merman. _You’re_ a kid.” It- _his_ -face has resurfaced, tinted pink from embarrassment, Hajime thinks. “And I’m not going to let you off easy just because you’re-” He stutters. “You’re _cute_.” It’s Hajime’s turn to blush, ears burning, and he swings himself back onto the dock. There’s a splash and he's dripping with water the next second, the mer _kid_ having vaulted himself practically into Hajime’s lap.

“You’re going to show me around the village.” He proclaims, holding fast onto Hajime’s soaked shirt. “As payment.”

“For _what_ ,” Hajime tries to shove him but something cold and wriggling has wrapped itself around his back, and Hajime realizes belatedly that it’s a _tail_. “Get off of me.”

“For being rude. And I’ve never seen it. Also for calling me a kid, I’m turning four millennia in a couple of years.” He ticks off the list on the same slender fingers that had dangled Hajime’s hook in front of him the night before. Hajime snorts, shoving a little harder. “ _And_ as thanks for me not cursing you and your whole family.”

Oh.

Hajime thinks his sisters might actually kill him if he gets them cursed again; the last time, it been a vindictive forest sprite that had made his family’s hair fall out. Hajime doesn’t want to find out if this merman is more creative. The village isn’t really _that big_ , he reasons.

“Whatever,” Hajime bites out. “But I’m not carrying you around the whole town.”

“I’m sure you _could_ ,” the creature leers, poking at Hajime’s arms, “I’ll take care of it. Come back tomorrow.”

He’s gone before Hajime can respond, traceless, and Hajime wonders how he’d gotten conned out of fishing for the second day in a row as the sun falls under the water.

 

***

 

There’s a boy on pier the next morning dressed in water-stained shorts and a t-shirt monogrammed with Hajime’s shop’s logo, dangling his feet off the end and skipping pebbles to skim across the surface of the shoreline. He turns when Hajime gets closer, grinning at him like they’re old friends and tugging at the hem of Hajime’s pants to make him sit down.

“It’s so calm,” he muses and kicks his legs, forcing the water to ripple and soak the bottoms of Hajime’s pants. “You’re not going to fish today?”

“I thought I was stuck _babysitting_ you?” Hajime responds, flicking his counterpart’s ear just to spite him, and ducking when a jet of water grazes the top of his head. “None of that,” he warns, “I don’t want to deal with people asking why I’m walking around the village with a merman.” It hits him, then, that the creature beside him looks about as human as Hajime does himself; there’s a smattering of blue scales the size of Hajime's fingernail on the backs of his hands and the side of his neck, but aside from that he’s all long, long legs and boyish grins. Hajime turns red when he finds he’s been caught staring, eyes following his own.

“Like it?”

Hajime coughs, standing up.

“Dumbass. You want to see the village or not?”

 

***

 

“My name’s Tooru, you can stop calling me ‘dumbass’.”

Hajime snorts, shoving a paper bag into Tooru’s hand and leaving coins on the wooden counter.

“I’m Iwaizumi.” Tooru rolls his eyes.

“I _know_ that,” he drawls, teasing. “I’m magic, remember?”

He doesn’t think about the eyes on them as they leave, Tooru’s presence vaguely enchanting, be it magic or the natural charisma he carries that has Hajime stopping at food stands for the idiot.

“‘Dumbass’ fits you better.” Hajime takes the bag from him and tears it open, breaking off a piece of milk bread and dropping it into Tooru’s palm. Tooru watches him chew and swallow his own, curious, and Hajime rolls his eyes. “You eat it?” He motions, taking another bite. Tooru shrugs, copying him, and Hajime thinks he should really be more shocked when the tips of Tooru’s fingers start glowing blue.

“It’s _good_ ,” Tooru plucks the bag from his hand, rifling through it. “Can we get more?” Hajime groans.

“You haven’t let me fish for the past two days, where do you think I’m going to get the money for-” Tooru’s wiggling sticky, glowing fingers in his face, close enough that Hajime goes cross-eyed.

“This means I liked it.” Tooru states, and Hajime sighs.

 _He_ doesn't even like milk bread, Hajime thinks as Tooru steps away from the stand with an armful of it and a smile that plays teasing and twisting at the pit of Hajime’s stomach.

 

***

 

Tooru stays at his heels until the sun begins to set, fading yellow turning his scales green and dark blue when light dips below the horizon and it becomes hard to see the cracks in the dock’s wooden planks.. Hajime’s gut twists when Tooru wades past shallow water, the fluorescent shimmer of his legs fusing visible underwater in Tooru’s own light. He waves back when Tooru does, lonely and faint, too far from the shore for Hajime to see Tooru’s face above the water.

Hajime sits on the pier afterwards. His eyes are tired enough that he thinks he can make out Tooru swimming down to wherever, whip fast and brighter than Hajime can stand to look at.

 

***

 

The village hasn’t been this productive in years, usually just kept afloat by the tiny troupes of tourists that passed through every so often. Hajime wants to accredit it to his fishing skills _finally_ paying off, but he knows it's Tooru, knows that it’s something in his magic that makes the orchards flower and fish come up with the tide even when the seasons drip into one another.

Hajime doesn’t see him, though, and the habit he’d made of checking under the dock when he visits each morning fades when Tooru stays gone but makes the village flourish like Hajime’s never seen it.

It’s years later when Hajime finds his spot on the pier taken again, and Tooru grins at him like it's been minutes rather than almost forever since they’d met before pushing Hajime off the dock and into freezing water the color of Tooru’s scales.

“This place has changed!” Tooru splashes him. Hajime’s heaving, breathing fast, and he chalks it up to shock and the niggling tremble in the back of his mind that _years have treated Tooru well_. “You’ve changed,” Tooru says this softly, but it's punctuated by another wave dousing Hajime.

“Now you come back,” Hajime mutters, spitting seawater from his mouth. Tooru waves him off.

“I couldn’t leave my patron city unattended, could I?” Tooru kicks, swift and strong, propelling him towards shore and whisking the sea foam surrounding Hajime. “You should show me what’s different!” Tooru calls, and Hajime follows, reckoning the village deserves more than to be exposed to Tooru without him chaperoning.

They're sitting at the dock again when Hajime remembers, nudges Tooru’s shoulder and doesn't think about how Tooru’s grown into himself, wiry yet strong.

Tooru’s also taller, infuriatingly so, a slight shift upwards that makes Hajime have to tilt his head towards the sky just the slightest bit to properly glare at him.

“What's a patron city?” Tooru stares at him for a minute, blinking owlishly.

“It’s hard to explain.” Hajime flicks his forehead.

“I’m not dumb.”

“That could be contested,” Tooru ducks away as he says it, laughing.

“Shut up. Answer my question, idiot.”

Tooru sighs.

“It’s a magic thing, magic isn’t meant to be explained, for god’s sake, Iwa-chan!” Tooru whines and wrings his hands, exasperated, as Hajime raises an eyebrow. “I’m bound to here.”

“Why?” Hajime catches the tips of Tooru’s ears flare red, spilling over his neck and the cut of his collarbones.

“If I knew, I’d tell you.” It’s dismissive, a shut door, and Hajime knows when to drop things.

 

***

 

Tooru doesn’t linger this time, tearing himself away from the shore and ducking underneath the waves without saying goodbye, and Hajime pretends it doesn’t sting like saltwater in his eyes.

 

***

 

“I think he knows.”

“I think you’re overreacting.” Keiji doesn’t even look at him.

“No, Keiji, he _knows_ ,” Tooru whines.

“Isn’t that a good thing? You were literally pining for years.”

“It’s too soon.” Keiji sighs and pushes Tooru’s tail from off of his legs.

“He’ll only grow older.” There’s something flickering behind Keiji’s impassivity, behind the schooled set his features usually have when he’s dealing with Tooru. “Human lives are pitifully short.”

 

***

 

Hajime wants to drown the next time he sees Tooru, months after he’d disappeared the last time, and _glaring_ at the girl sitting beside Hajime on the dock as if she’d clipped his fins.

“Hajime-kun, you didn’t tell me you knew a merman!”

“I wish I didn’t,” Hajime mutters, and it’s just a _little_ funny when Tooru submerges himself and splashes Hajime and Hiyori-chan with enough water to make them shiver.

Hiyori leaves after Tooru’s sixth splash, relentless, and Hajime tries not to laugh at how utterly petty he’s being.

“You’re not going to follow her?” Tooru asks, but there’s light in his eyes that give him away, and Hajime shakes his head.

“The sun’s just starting to set.”

Tooru nods, hoisting himself onto the pier. His tail has disappeared, split into long, long legs in a pair of shorts Hajime has to avert his eyes from.

“They’re the only one’s I could find, Iwa-chan, don’t be lewd.” Tooru’s blushing despite himself, staring determinedly out towards the horizon and kicking his feet.

“You’re back, then?” Hajime follows the drop of the sun, ricocheting light as it hits the water and turning Tooru’s skin almost gold.

“Yeah,” Tooru purses his lips. “Not forever, though.”

Hajime snorts, shoving him.

“Forever’s too long, anyways.”


	2. Chapter 2

**Notes for the Chapter:**

> i decided to make this three parts (probably)! finals are approaching so please forgive me for the gaps between chapters.

Tooru invites himself inside without asking, draping himself over Hajime’s ancient, threadbare couch and staring at the inside of the weathered cottage with a glow in his eyes that Hajime thinks might actually be there, magic be damned.

“Do mermen sleep?”

“Obviously,” Tooru’s smiling at him, tucking his feet under Hajime’s calves when he sits beside him.

Hajime can’t find it in himself to move, not when Tooru’s warm and uncharacteristically quiet, pensive maybe. Hajime didn’t know such a thing as a thoughtful Tooru existed, but then again, he didn't believe he’d ever meet a merman, either.

“Are all humans this lonely?”

“I could’ve had a girlfriend by now it it weren’t for you.” _If it weren’t for you._ “My sisters live on the mainland, and my parents-” Hajime purses his lips, “don’t.” Tooru stills where he’s pressing his toes beneath Hajime’s legs, a barely-there “oh” tumbling from his lips as if he hadn’t meant to say it at all. “It was years ago.”

“You don’t have to explain.” Tooru says, nudging him.

Hajime folds his arms in front of his chest and tries to temper the furious rush of blood to his face. He hopes Tooru’s not powerful enough to distinguish the rapid-fire thrum of his heartbeat.

He looks up just as Tooru’s expression morphs, catches a flicker of something frightened and so _raw_ that leaning in is instinctive, the soft give of Tooru’s mouth beneath his own liquidating his senses until he’s less than a puddle in Tooru’s hand, dripping through his fingers.

Kissing Tooru is wet, and Hajime wonders why he’d ever thought it’d be any different. There’s salt on his tongue and fingers weightless on his jaw, his forehead, and tangling in the hair at the back of his neck, and it occurs to him that Tooru’s probably done this before, that Tooru’s ages older than he is and some merman _prince_ or something and Hajime’s pitifully human and clumsy and probably freaking him out with his weird human feelings-

Tooru keens, scrabbling against Hajime’s chest, and Hajime’s second thoughts dissolve when Tooru pulls them down onto Hajime’s couch.

“Don’t flatter yourself. I’m not used to these,” He kicks his legs, spreading them and hooking his ankles around Hajime’s back when he falls between Tooru’s thighs. Hajime kisses him again, buries himself in every slow drag of Tooru’s hands over his skin and press of lips on his neck.

It’s remarkably easy to leave marks on Tooru, Hajime notes, observes this as Tooru’s breathing hard once Hajime’s stopped bruising a galaxy onto his neck. Tooru stares down at him, shivers when Hajime’s hands linger tentatively at the crevices of his hipbones and _push_ , and he plants both hands on either side of Hajime’s face to pull him up.

“I’m not sure how it all works.” Tooru whispers, embarrassed and cloud-soft against Hajime’s lips. “Like, what in the world is _this_?” Tooru’s hands are on him, the heel of his palm firm at the front of Hajime’s shorts, and Hajime chokes on a gasp.

“Cheater,” he laughs. Tooru’s grin bleeds mischief, the iridescence of scales on the side of his neck flashing with whatever magic pulses there.

“Show me the rules, then.” Tooru arches up to kiss him again, nicking his sharp teeth on Hajime’s bottom lip and setting a fire in his veins that mirrors the starburst flares under Tooru’s skin.  

Hajime finds that Tooru’s a quick learner, all alert eyes and dangerous smiles and noises kindling warmth in the pit of his stomach, tricking him into saying things that probably make Tooru’s ego soar. He wakes up with arms around his waist and circlet of blue flame hovering above them, sparking intermittently with Tooru’s snores.

 

***

 

Tooru insists on wearing nothing but Hajime’s shirt when they finally get out of bed, hanging too-loose from his shoulders and baring enough skin that Hajime walks into the wall a couple of times.

It’s a sight Hajime finds himself cataloging, storing alongside Tooru breaking the coffee maker, Tooru kissing him, _Tooru_ , as if he’ll forget if he doesn’t think about it enough.

Ankles knock against his own as they eat breakfast, Tooru’s feet cold where they travel below the hem of his pajamas before moving down and kicking him again, and it’s the sort of domesticity that sends Hajime reeling, dizzy, and he thinks only after an eternity of this will he be satisfied.

 

***

 

The town welcomes Tooru like he’d never been gone; Hajime tampers down the twinge of annoyance when Tooru gets stares far too lingering for his liking. Tooru sits beside him while he fishes and hums softly, his legs fusing back into a tail when he lets his feet touch the water.

“The palace is bigger than your village,” Tooru tells him, “huge. And blue, like this.” There’s a flame the size of a coin in Tooru’s palm, the same cerulean color as the glow Tooru gives off sometimes. “I live there.”

Hajime reels in his line, listening absently.

“Are you the only one that comes to the surface?”

Tooru shrugs. “My friend Keiji used to visit a while ago.”

“He doesn’t anymore?”

“Says he doesn’t have a reason to.”

“And you do?” Hajime feels heat crawl up his neck and settle at the tips of his ears. Tooru’s silent beside him, blue threading through the veins in his arms, and Hajime clears his throat to apologize but Tooru slots their mouths together, soft and tentative.

“Yeah, I do.”

 

***

 

Hajime doesn’t notice Tooru’s glow subsiding until it’s nearly gone, barely there after a week of being here with him, and he flinches like it hurts when Hajime presses down on his pulse.

“There’s not a lot of light anymore. Is that bad?”

“I feel fine,” Tooru replies, burrowing further into Hajime’s side and sighing. “Tired, though. I think it’s because of being away from the water for so long.”

“We’ll go to the beach tomorrow.” Hajime takes Tooru’s hand in his own, links their fingers and wraps his free arm around Tooru’s shoulders.

Tooru falls asleep quickly. The gentle tide of his chest leads Hajime halfway there until he’s suspended; it’s during the weightless lull between asleep and awake in which Hajime finds a name for the sweet pressure spiralling towards his stomach.

 

***

 

“I’m not turning.” Hajime’s gaze falls to Tooru’s legs, submerged up to his thighs and still separated, still achingly human. “Nothing’s happening.” It’s panicked, torn from Tooru's throat, and Tooru’s nails dig into his arm, hard enough to draw blood but doing little to drag Hajime’s eyes from the tears collecting at the corners of Tooru’s eyes. “I can’t stay here, Hajime.”

Hajime’s gut twists, knocks the air out of him.

“You could,” he tries, but Tooru scoffs, winces, pulls his fingers from Hajime’s arm and steps back.

“You think it’s that simple? That I can just _turn human_?” He’s frenzied, almost feverish, and the water around his legs begins to froth, bubbling until it’s so warm Hajime recoils. _“I have to go back.”_

“Tooru-”

“Don’t.” His tears glow blue, leaching color from his skin and hollowing, carving Tooru’s cheekbones into his face. Hajime swallows, feels his own eyes prick, and steps forward. The water scalds his legs and Hajime’s stomach turns when he catches a glimpse of Tooru’s lower half; he's turned, but his tail is tattered, shreds of scales giving way to red, raw skin, and Tooru’s bleeding, saturating the water with it.

“I’m gonna swim down.”

“You’re _not_.”

Tooru yelps when Hajime touches his arm, the bare brush of his fingers leaving Tooru’s skin an angry crimson that Hajime can't look at, and he’s gone before Hajime can reopen his eyes.

He focuses on breathing, counts his inhales and shakes with each one, scrubs the red from under his fingernails and tries to scrub away Tooru with it, but salty air still follows him into his bedroom and Hajime still wakes come morning with the taste of seawater on his tongue.

 

 

 


End file.
